Erasers suitable for permanent attachment to a pencil are typically solid and cylindrical in shape. The eraser is attached to the lead-bearing, wooden portion of the pencil by a metal collar or ferrule that permanently attaches the eraser and the lead-bearing portion. Removable erasers for pencils are also known, which typically consist of a tubular bottom integrally formed with an arrow-head shaped top. The tubular bottom is sized to fit over a used (or unused) cylindrical eraser and frictionally engage the ferrule.